Total Annual Value Research Articles

Effects of urbanisation on ecosystem service values: A case study of Nha Trang, Vietnam.

Anthropogenic activities have significantly reshaped the environmental landscape and altered land composition, thereby negatively affecting the structures and functions of ecosystem. Paradoxically, complex conditions and procedures of ecosystem operations generate a range of goods and services on which humans rely upon to thrive. This study examines the land-use transition and ecosystem service value changes in Nha Trang, Vietnam in order to understand and quantify the impacts of urbanisation patterns on ecosystems. Changes in the value of ecosystem services were acquired based on modified value coefficients from previous studies and land-use/land-cover information derived from Landsat satellite imagery in the years 1990, 2000, 2011, and 2020. The results show a significant decrease in ecosystem service value associated with the expansion and densification of urban areas over the past 30 years. Total annual value increased from 148.7 million USD in 1990–172.2 million USD in 2000 due to the success of forest rehabilitation efforts, followed by a decline to 149.3 million USD in 2020 because of the rapid development of urban agglomeration at the expense of cultivated land. Drawing from the outcomes, we suggest that the priority of regional land-use planning should be given to ecosystem-based approaches rather than inadequate urban expansion. Hence, guidelines to incorporate the ecosystem service concept into urban planning are proposed to promote climate-resilient city management and sustainable development.

Soil–vegetation moisture capacitor maintains dry season vegetation productivity over India

India receives more than 70% of its annual rainfall in the summer monsoon from June to September. The rainfall is scanty and scattered for the rest of the year. Combining satellite data and model simulations, we show that the soil-vegetation continuum works as a natural capacitor of water, storing the monsoon pulse and releasing the moisture to the atmosphere through evapotranspiration over approximately 135 days when the moisture supply from precipitation is less than the evapotranspiration losses. The total Gross Primary Productivity of vegetation in India during the capacitor period accounts for almost 35% of the total annual GPP value. It primarily depends on the soil moisture at the beginning of the period, a measure of moisture capacitance of soil, with a correlation of 0.6. Given that India is the second largest contributor to recent global greening, its soil-vegetation water capacitance plays a significant role in the global carbon balance.

Ecological Service Function Evaluation and Sustainable Development Countermeasures of Plateau Wetland Ecosystem: A Case Study in Lashihai Nature Reserve, PRC

The Nature Reserve plays a very important ecological role in many ways, such as soil-water conservation, flood-drought prevention, and water balance. Thus, protecting and maintaining the wetland and other crucial components of Lashihai Nature Reserve are of great importance not only to the natural environment and biodiversity conservation, but also to the development of regional economic as well as social stability. Based on the characteristics of plateau wetland of Lashihai Nature Reserve in Lijiang City, Yunnan Province, this study tried to establish an evaluation system. It is mainly aimed at evaluating the direct and indirect use value of the ecosystem service value of this vary wetland reserve. The results showed that: the total annual ecosystem service value of Lashihai Nature Reserve is 198.44 million yuan. Among all kinds of values, the climate regulation value ranks first with 79.35 million yuanꞏa-1, accounting for 39.99% of the totality, then followed by the tourism value and resources value, while the water purification value comes the last with 0.48 million yuanꞏa-1.

RADIOLOGICAL ASSESSMENT OF NATURAL RADIOACTIVITY IN A URANIUM DEPOSIT AREA: KÖPRÜBAŞI, TÜRKIYE.

In this study, the results of environmental radioactivity studies conducted in Köprübaşı, Manisa district, where Türkiye's uranium mineral exploration and processing studies were carried out, are shared. Because this is a populated area, there is a need for radio ecological dosimetry assessment to investigate the possible risk to the population. The region where radiological monitoring is carried out is discussed in two parts as the areas where uranium mineral exploration is performed and the settlements close to these areas. It was observed that 714-4714 nGy/h values were obtained in the outdoor absorbed dose rate in air measurements taken in the areas where mineral exploration was performed and this value reached up to 22857 nGy/h in open field mining areas. In the residential areas, it was recorded that the outdoor absorbed dose rate in air values ranged between 142 and 242 nGy/h and the indoor values ranged between 171 and 400 nGy/h. The world absorbed dose rate in air average values is 57 nGy/h (outdoor) and 75 nGy/h (indoor). The high 226Ra values in the radioactivity analyses of the soil samples draw attention. The mean values of the activity concentrations of the radionuclides 226Ra, 232Th and 40K in the soil samples are 3169, 55 and 802Bq/kg and the world averages of these values are 35, 30 and 400Bq/kg, respectively. It was determined that high 226Ra value in the soil in the areas close to the open field uranium mining area was passed on to the agricultural products. Radioactivity measurement results of drinking water samples did not exceed World Health Organization guidelines. According to the radon gas measurement results of 44 houses in Köprübaşı villages, the average radon concentrations in winter, spring, summer and autumn seasons were 72, 61, 50 and 55Bq/m3, and the annual average value was 60Bq/m3, respectively. Although these values are greater than the world average of 46Bq/m3, they are below the recommended limit value (100Bq/m3). By evaluating the data obtained, the total annual effective equivalent dose values (originating from outdoor-indoor absorbed dose in air, drinking water and indoor radon gas concentration) to which the people in the region are exposed were calculated as a 3.12mSv.

ECONOMIC VALUE OF WILDLIFE SANCTUARY: A CASE STUDY FROM THE WESTERN GHATS IN KARNATAKA, INDIA

Goods and services of the ecosystem provided by the natural environment have not been considered in terms of their economic value. There are a number of studies that have estimated the economic value of forest ecosystem services in India, but very few studies have estimated these economic values of other important ecosystem services. Biligiri Rangaswamy Temple Wildlife Sanctuary (BRTWLS) is a unique place as a bridge between the Western Ghats and the Eastern Ghats in Karnataka, India. There are 12,500 Soligas (tribal community) living in this area. Non-timber forest products constitute more than 60% of the Soliga household income. A number of studies have been conducted in the BRTWLS. However, there is a lack of studies on the economic value. The primary objective of this study is to estimate the value of ecosystem services provided by BRTWLS. This study has used the market price methods for estimating the value of provisioning services and individual travel cost method for estimating the value of recreation services, while the value of carbon sequestration and soil erosion prevention has been estimated based on secondary data. This study has estimated the total annual value of provisioning, regulating and cultural services of BRTWLS at Rs 23.9 million y-1. The findings of the study will be helpful to the local policy makers to increase the entry fee at the BRTWLS, as it provides valuable ecosystem services and reinvests the same in natural capital to achieve environmental sustainability at the local level.

Investigating the Effect of Shading on the Capacity Factor of Floating Photovoltaic Systems

In this study, remote sensing (RS) was used to determine the 20-year area and shoreline changes of Demirköprü Dam reservoir. Using a geographical information system (GIS) solar analysis tool, annual and monthly total global horizontal irradiance (GHI) values were calculated within the area of the reservoir’s shorelines based on 20-years of observations. The regional theoretical capacity factor (RTCF) proposed in this study was modelled using total annual GHI values. The water surface was divided into four regions using RTCFs 94.97%, 4.92%, 0.08%, and 0.02% of the total water surface area were classified as RTCF21, RTCF20, RTCF19, and RTCF18, respectively. The annual electrical energy potentials per unit for each RTCF were calculated. The novel method developed in this study for determining the optimum location of FPV SPPs to be installed on water surfaces reveals the importance of evaluating land topography and considering annual patterns of shading.

Spatial and Temporal Change of Reference Crop Evapotranspiration in Marmara Region

Bu çalışmada, Marmara Bölgesinde bulunan 18 meteoroloji istasyonu için 1990-2020 yılları arası aylık iklim verileri kullanılmış ve FAO Penman-Monteith yöntemi ile yıllık toplam ETo değerleri tahmin edilerek alansal ve zamansal değişimleri değerlendirilmiştir. Bu amaçla, her bir istasyon için parametrik olmayan Mann-Kendall testi ve Sen yöntemi kullanılarak yıllık toplam ETo eğilimleri belirlenmiş ve coğrafi bilgi sistemleri (CBS) Ters Mesafe Ağırlıklı (IDW) enterpolasyon yöntemi kullanılarak ta ETo haritaları hazırlanmıştır. Çalışma sonuçlarına göre, yıllık toplam ETo değerleri 742.3-1440.7 mm arasında değişim göstermiştir. Edirne, Kocaeli, Sakarya, Bozcaada, Çanakkale, Kırklareli, Uzunköprü, Tekirdağ, İpsala ve Dursunbey istasyonları için ETo değerlerinde istatistiksel olarak önemli artış eğilimleri belirlenirken, Kumköy-Kilyos ve Keles istasyonları için eğilimler önemli düzeyde azalan yönde olmuştur. Bununla birlikte, Bandırma, Bursa, Şile, Florya ve Gönen istasyonları için gerçekleşen ETo artış eğilimleri ile Bilecik için belirlenen azalış eğilimi istatistiksel olarak önemli olmamıştır. Yıllık ortalama ETo haritası değerlendirildiğinde, Marmara Bölgesi’nin batı kesimlerinde (Edirne’nin güneyi, Balıkesir’in batısı ve Çanakkale) ETo yüksek değerlere ulaşmıştır. Bölgenin kuzey kesimlerinde; Kırklareli ve Tekirdağ’ın doğusunda ve bölgenin doğu kesimlerinde; İstanbul’un doğusu, Kocaeli ve Sakarya’da ETo değerleri düşmüştür. Ayrıca Kırklareli, Tekirdağ’ın doğusu, Kocaeli ve Sakarya’da uzun yıllar ortalama ETo değerleri düşük bulunurken, bu illerde ki meteoroloji istasyonları verilerinden hesaplanan yıllık toplam ETo değerlerinde istatistiksel olarak önemli düzeyde artış eğilimleri belirlenmiştir.

지불의사금액 추정을 통한 학교체육 활성화 정책의 경제적 가치 추정

The purpose of this study is to quantitatively calculate the benefits of invigorating policy for physical education in school through CVM. In order to select the distribution of the amount to be used in the survey, a preliminary survey was conducted with 100 people, and the maximum amount of annual tax payable for the invigorating policy for physical education in school was investigated using an open-ended question method. This survey was conducted for a total of 649 people by randomly allocating all respondents to each suggested amount, and 45 people were confirmed to have responded with resistance. carried out. In this study, the Turnbull non-parametric estimation method was applied to estimate the WTP. As a result of the estimation, the annual amount of WTP per household for the invigorating policy for physical education in school was 15,820.7 won in the SBDC model and 16,889.5 won in the DBDC model, respectively. When this is reflected in the entire population, the annual total economic value of the invigorating policy for physical education in school is estimated to be approximately KRW 51.6 billion in the SBDC model and approximately KRW 55.1 billion in the DBDC model. The above amount can provide the following positive implications regarding the effectiveness and continuity of the project by comparing it with the actual cost of invigorating policy for physical education in school.

Evaluation of environmental radioactivity in soils around a coal burning power plant and a coal mining area in Barapukuria, Bangladesh: Radiological risks assessment

To study the distributions and potential dispersions of naturally occurring radioactive materials (NORMs: 226Ra, 232Th, and 40K) from coal-based activities (Barapukuria, Bangladesh), we studied a suite of systematically collected surface and sub-surface soil samples by X-ray fluorescence and high purity germanium detector based γ-spectroscopy. The average (range) radioactivities of 226Ra, 232Th, and 40K in the studied soil samples were 80.6 (33.0–118.0), 104.4 (43.0–182.0), and 508.1 (318.3–743.4) Bq.kg−1, respectively, which are significantly higher than the corresponding world average value. No significant fractionations of NORMs were observed between the surface and sub-surface soils, except for 232Th. Along with the anthropogenic origin, several geochemical processes (e.g., weathering, mineralogical dissolution/precipitation, alteration, leaching, differential solubility mediated geochemical mobility etc.) play significant role in NORM distributions. Major-oxide abundances, indices-based calculations, and correlation studies on the measured parameters revealed the natural processes (e.g., geochemical mobility, mineralogical distributions, water logging based differential solubility) responsible for NORM distributions. In terms of mean radium equivalent activity, internal hazard index, and total annual effective dose values, the studied area possesses trivial radiological risks, whereas the values of internal absorbed gamma dose and excess lifetime cancer risk demonstrate significant health hazards. Considering the adverse radiological risks originating from coal-based industrial activities and the long half-lives of NORMs, the present scenario will potentially be deteriorated.

Identification of homogeneous regions based on rainfall in the Amazon River basin

AbstractThe identification of homogeneous rainfall regions facilitates the prioritization of watershed management measures. In the present study, it was applied the methodology of data clustering by the non‐hierarchical method of fuzzy C‐means, having as variables the geographic coordinates (latitude and longitude) and average annual precipitation, provided by the Global Precipitation Climatology Center (GPCC). The group formations were validated by Silhouette, PBM, Dunn, Davies Bouldin, and Xie Beni. The total annual precipitation values found for the regions are consistent with the precipitation volume recorded in the analysed region and found in the literature. The results presented satisfactory data from the application of the methodology, from which six homogeneous regions of well‐defined precipitation were formed, each with its own particularity, demonstrating the spatial–temporal variability of annual precipitation totals in the region. When analysing the climatological normals in relation to previous studies, a change in rainfall behaviour was noted, with changes occurring in the months with higher and lower average rainfall records in the area, mainly in homogeneous regions (HRs) 3 and 6. HRs 1 and 6 showed a unique behaviour, with their climatological normals different from the others.

Integrating life cycle assessment and a farmer survey of management practices to study environmental impacts of peach production in Beijing, China.

While intensive peach production has expanded rapidly in recent years, few studies have explored the environmental impacts associated with specific regional systems or the optimal management strategies to minimize associated environmental risks. Here, data from a survey of 290 native farmers were used to conduct a life cycle assessment to quantify the acidification potential (AP), global warming potential (GWP), eutrophication potential (EP), and reactive nitrogen (Nr) losses in peach production in Pinggu District, Beijing. Total annual Nr losses, and GWP, AP, and EP values for peach production in Pinggu District were respectively 10.7kgN t-1, 857kg CO2-eq t-1, 12.9kg SO2-eq t-1, and 4.1kg PO4-eq t-1. The principal driving factors were fertilizer production, transportation, and application, which togetheraccounted for 94%, 67%, 75%, and 94% of Nr losses, GWP, AP, and EP, respectively. In the high yield, high nitrogen-use efficiency (HH) group, relative values of Nr losses, GWP, AP, and EP were respectively 33%, 25%, 39%, and 32% lower than the overall averages for 290 orchards. Further analyses indicate that improved farming practices such as decreasing application rates of fertilizers, increasing proportion of base fertilization rate, and proper fertilization frequency in the HH group were the main reasons for these orchards' better performance in peach yields and partial factor productivity of nitrogen fertilizer, and their reduced environmental impacts. These results highlight the need to optimize nutrient management in peach production in order simultaneously to realize both environmental sustainability and high productivity in the peach production system.

Radiation Health Hazard and Risks Assessment Among Greenhouse Farmers in Egypt, seasonal Study.

Objectives Greenhouses have been rapidly developing in Egypt in the recent years so as to overcome the problem of water shortage required for agriculture because agriculture in protected houses provides about 20-40% of the water consumption from agriculture in open lands. Greenhouses are widely used to cultivate different kinds of plants. Greenhouses are considered spacious, enclosed areas, in close contact with airtight and soil. They have been the main radon source for a long time. Radon and its progeny are released and trapped in the vacant space of greenhouses, causing health hazards for the farmers who work in them. Taking this into consideration, seasonal radon concentration levels have been monitored and measured in 8 greenhouses located at the city of Alexandria and Rosetta, Egypt. Materials and Methods Passive closed-and-open can techniques are mainly used to calculate these concentrations. Each can has an attached CR-39 polymeric nuclear track detector as a detector material. For a period of one year inside the chosen greenhouses, the dosimeter has been exposed to the local for four seasons, 3 months each. Results The average annual radon concentration in those greenhouses varies between the lowest radon concentration value of 310 ± 86 Bqm−3 in the glass greenhouse in Alexandria, and the highest concentration value of 543 ± 88 Bqm−3in the plastic greenhouses in Rosetta, with a total average annual value of 476 ± 68 Bqm−3 . A remarkable variation in the seasonal radon concentrations in the greenhouses is observed. Also, in the research at hand, the radon radiation dose received by a farmer working in the greenhouses is calculated according to the ICRP (ICRP, 1993).The occupants' greenhouse exposure rate varies from 1.38 mJ h m−3 (0.39 WLM) in the plastic greenhouses to 2.42 mJ h m−3 (0.683 WLM) in the glass ones, with an average value of 1.68 mJ h m−3 (0.55 WLM) during that year. The workers' estimated effective dose per annum ranges between 1.94 mSv and 3.39 mSv with an average dose of 2.73 mSv. Conclusion In all the examined greenhouses in the Egyptian cities of Alexandria and Rosetta, the estimated effective dose per year is in the lower limit range of the action level (3–10 mSv) recommended for greenhouse workers by the ICRP (ICRP,1993), and it does not exceed the ICRP's upper limit. If the farmers work for a long number of years in the greenhouses, the occupational exposure to radiation doses due to radon concentration must be taken into consideration.

Energy recovery from municipal solid waste landfill for a sustainable circular economy in Danang City, Vietnam

Sustainable development of Danang City in the direction of circular economy (CE) and a zero-waste city is an urgent solution because the impacts of local municipal solid waste (MSW) generation in the city’s districts are increasingly causing serious pressure for MSW management and treatment. Segregation of waste at source, reuse, recycling, and energy recovery from landfill gas (LFG) generated is considered as one of the keys to solving the dilemma of sustainable waste management. This study analyzed and evaluated the generation of greenhouse gases (GHGs), mainly CH4 and CO2 gases from the Khanh Son landfill based on the application of the EnLandFill software and assessed the potential of energy recovery, clean electricity generation, as well as GHG emission reduction in the period of 2021 – 2050 based on the CE-oriented scenario of the city government. With the potential to recover LFGs in the period of 2021 – 2050 could reach 136.9 million m3 (with efficiency E = 90%), the total annual potential value of electricity generation is estimated at 420.767 million kWh, equivalent to the total potential for GHGs emission reduction (GWP) about 271.25 thousand tCO2-eq. At the same time, this will be a baseline study to serve as the basis for extensive assessments and to suggest the most appropriate waste management strategies and policies create a circular economy in the future.

Assessment of Concentration, Erosivity and Seasonality of Precipitation Data for 1970-2019 Period of Karataş Gauging Station

Temporal and spatial variations in precipitation as a result of the effects of climate change generally cause a flood, drought, soil erosion, etc. events to occur. For this reason, determining the precipitation variability in a region is quite important in protecting soil and water resources and in struggling soil erosion. This study aims to examine the monthly and annual variation of precipitation, annual and seasonal precipitation concentration (APCI and SPCI), annual and seasonal precipitation erosivity (AMFI) and SMFI, and seasonality of precipitation (SI) of the Karataş meteorological station in the Seyhan Basin for the period 1970-2019. In addition, the change of these parameters in the examined period was examined using the Mann-Kendall (MK) trend test. According to the results obtained, generally irregular and strong irregular precipitation distribution was obtained in the APCI values calculated for the Karataş station. According to SPCI analysis, SPCIWinter values are uniform and moderate, SPCISpring values are moderate, SPCISummer values are strongly irregular, and SPCIAutumn values have moderate precipitation distribution. According to the AMFI values calculated to examine the precipitation erosivity, it was determined that the precipitation generally constitutes a high (34%) and a quite high (40%) erosion risk. According to seasonal MFI analysis results, SMFIWinter values generally show a high and very high erosion risk, SMFISpring and SMFISummer values show no or very low erosion risk, and SMFIAutumn values show moderate, high and very high (about 62%) erosion risk. According to the SI analysis results of the 50-year study period, about half of the SI values represent significant seasonal precipitation with a long dry season. The Mann-Kendall trend results of monthly total precipitation, annual total precipitation, APCI, SPCI, AMFI, SMFI and SI values show that there are no significant trends for the 1970-2019 period.

Analysis of Climate Parameters as Indicators of Climate Changes in Central and Eastern Iraq: Khanaqin Climate Conditions as A Case Study

The climate parameters of rainfall, and average of maximum and minimum temperature were investigated for the period of 2000-2019 in three stations in central and eastern Iraq (Baghdad, Diyala, and Kut provinces). Evidence of climate change was noticed from the results, reflected by decreased mean values of annual rainfall with increased mean of maximum and minimum temperature. In addition, the water balance and the climatic conditions were determined for Khanaqin station for the years 1981-2019. The analysis of Khanaqin climate parameters demonstrated total annual mean values of rainfall of 260.86mm and evaporation of 3119.59mm. The mean monthly relative humidity was 46.65%, sunshine was 8.39h/day, temperature was 23.36Co and wind speed was 1.86m/sec. Water surplus was recorded in Khanaqin area, with values of (24.00mm) (34.18mm) (40.31mm) (28.83mm) and (19.92mm) in November, December, January, February and March respectively. The climate classification of Khanaqin area indicated semi dry and dry climates. Moreover, the region has water deficit that reached up to 43.56 % of the total rainfall values.

Separation of nitrogen from methane by multi-stage membrane processes: Modeling, simulation, and cost estimation

This study focuses on the application of multi-stage membrane separation processes for the removal of nitrogen from natural gas. Reliable modeling and process simulation are essential for the analysis of the gas separation process. A mathematical model was developed using thermodynamic models, like lattice fluid (LF) and non-equilibrium lattice fluid (NELF), for gas sorption and transfer model for gas diffusion in the membrane. The proposed mass transfer model was validated with the experimental data for the gas solubility and permeability in various glassy and rubbery membranes. Then the proposed model was coupled with Aspen Plus software (Aspen Tech) for simulation of different proposed configurations of the multi-stage membrane processes. The performance of various gas separation configurations was investigated in terms of product purity, methane recovery, total capital investment, and total annual cost. The results indicated that the membranes with higher permeability had more suitable economic parameters. For example, the total annual cost for the AF1600 membrane was seven times the total annual cost value for the PTMSP membrane in the single-stage membrane separation process. It was observed that the methane purity of above 96 %mol and methane recovery of 90% could not be achieved by the single-stage process. However, the specified separation criteria can be achieved via the multi-stage membrane processes by two or three membranes. The best configuration was selected from various proposed configurations by evaluating the economic parameters.

Estimation of land-based emissions during container terminal operations in the Ambarlı Port, Turkey

Many types of mobile vehicles are used simultaneously in container terminal operations. Because most of these mobile vehicles have diesel engines, they emit a significant amount of pollutant emissions into the atmosphere during their operation. They are considered as land-based mobile emission sources (MobES) and should be included in the total port emission inventory. The emission inventory is a basic requirement in developing an environmental management strategy to improve emission control. In this context, this study aims to estimate the emission inventories of mobile vehicles used in terminal operations in the Ambarlı container ports located in the city of Istanbul, which is one of the most populous cities in the world. In this respect, the amounts of the emissions of all the container handling equipment with diesel engines in the port areas, including external trucks delivering/receiving containers to/from the port were estimated using an activity-based method. It has been found that approximately 42.39% of the total CO2 emission is owing to terminal tractors and the total annual CO2 value per TEU (Twenty-foot Equivalent Unit) of MobES is 0.01259 tons. The CO2 value per TEU can serve as a CO2 emission performance indicator for land-based MobES in process of the evaluation of emission inventories in container ports.

The recreational value of a peri-urban forest in Morocco

Peri-urban forests provide a range of important benefits to urban dwellers, such as, for example, nature-based recreation. This cultural ecosystem service is of significant importance in the developing world: It helps to increase urban resilience and stress recovery, which, in turn, can help mitigate many urban-life-related psychological and physical health issues, and socio-cultural problems caused by rapid urbanization and population growth. However, in developing countries such as, for example, Morocco, the heavy use of peri-urban forests for recreation and the limited management funds that do not keep up with the growing need for development and conservation result in anthropogenic pressures that lead to the degradation of these valuable natural sites. Non-market valuation of peri-urban forest recreation can help inform decision-making, conceive more effective management of these natural areas and increase funding for their conservation. This study estimates the recreational benefits of Val d’Ifrane, a broad peri-urban forest within Ifrane National Park in Morocco, to its domestic visitors, thereby filling a research gap in the non-market valuation of nature-based recreation in developing countries in general, and the geographic region of Morocco specifically. The study uses the individual single site Travel Cost Method with a correction for zero-truncation and endogenous stratification to estimate the recreational use-value of Val d’Ifrane. Results suggest an annual recreational value of 159.59 million DH (€ 14.71 million) or an average of 1,063.94 DH (€ 98.08) per visit per year (confidence intervals of 12.78 million DH (€ 1.17 million) to 306.40 million DH (€ 28.24 million) per annum, or 85.21 DH (€ 7.86) to 2,042.68 DH (€ 188.30) per visit per year). Robustness of the results is tested with regard to the operationalization of the travel cost and the opportunity cost of time, as well as the consideration of multi-site and multi-destination trips. The total annual recreational value is found to be 35 times higher than the cost for the last management and investment carried out by local environmental authorities in more than ten years. This information can assist decision-makers in their deliberations on funding for Val d’Ifrane restoration and development to maintain its recreational value while minimizing the negative impacts on natural capital and preserving the site for future generations.

Evaluation of wetland ecosystem services in green core of Changzhutan urban agglomeration, Hunan

Wetland in Changzhutan green core area of Hunan Province provides a number of ecosystem services for local urban construction and economic development. The evaluation of wetland ecosystem services may provide the wetland value data for the construction of Changzhutan urban agglomeration, and provide the basis for the creation of ecological compensation for wetland ecological protection. In this study, 8 service functions: water conservation, pollution degradation, carbon fixation & oxygen release, soil fixation & fertilizer preservation, nutrient accumulation, microclimate improvement, habitat provision provision, and scientific research & culture recreation were selected to evaluate the ecological service functions of wetlands in the green core area. The results showed that: (1) The total value of wetland ecological services in the green core area was 748 million yuan/a, among which the water conservation function was the dominant service function, with the highest value (319 million yuan), followed by the carbon fixation & oxygen release function and the pollution degradation function (156 million yuan and 125 million yuan, respectively). (2) From the perspective of the three prefecture-level cities, the total annual ecological value of Changsha wetland (353,007,600 yuan/a) was the highest, followed by Xiangtan (268,140,900 yuan/a), and Zhuzhou (126,749,900 yuan/a) was the lowest. (3) From the perspective of each district and county, both the total value and individual value of wetland service functions are the highest in Yuetang District, followed by Yuhua District and Tianxin District, and the lowest in Xiangtan County. The research results may provide a reference for the construction of wetland ecosystem service evaluation index system, strengthen the protection and utilization of wetland resources, and provide data support for the improvement of ecological civilization in Changzhutan urban agglomeration.

Spatio-Temporal Variation Characteristics of Aboveground Biomass in the Headwater of the Yellow River Based on Machine Learning

Accurate estimation of the aboveground biomass (AGB) of grassland is a key link in understanding the regional carbon cycle. We used 501 aboveground measurements, 29 environmental variables, and machine learning algorithms to construct and verify a custom model of grassland biomass in the Headwater of the Yellow River (HYR) and selected the random forest model to analyze the temporal and spatial distribution characteristics and dynamic trends of the biomass in the HYR from 2001 to 2020. The research results show that: (1) the random forest model is superior to the other three models (R2val = 0.56, RMSEval = 51.3 g/m2); (2) the aboveground biomass in the HYR decreases spatially from southeast to northwest, and the annual average value and total values are 176.8 g/m2 and 20.73 Tg, respectively; (3) 69.51% of the area has shown an increasing trend and 30.14% of the area showed a downward trend, mainly concentrated in the southeast of Hongyuan County, the northeast of Aba County, and the north of Qumalai County. The research results can provide accurate spatial data and scientific basis for the protection of grassland resources in the HYR.